Under the Sea Sunstone Carving

The minerals in the feldspar family make up more than half of the Earth’s crust. Occasionally these common minerals form crystals that exhibit a sheen, an optical phenomenon called aventurescence or schiller. Sunstones exhibit a reddish to golden schiller, resulting from light reflecting off numerous tiny copper or hematite (iron oxide) flakes scattered within the stones. Varying amounts of copper, as well as the size of the copper inclusions, cause the Oregon sunstones to range in color from colorless to yellow, as well as shades of green, red and pink. Some gems contain several colors, as seen here. These sunstones from Plush, Oregon are a variety of the plagioclase feldspar mineral labradorite. The name “sunstone” has been used for feldspars that exhibit schiller, however, the term is also used for Oregon gems with and without the schiller effect. The 43.81ct sunstone pictured here, titled Under the Sea, was carved and faceted by award-winning gem artst Darryl Alexander and donated to the National Gem Collection by Doug and Robin Malby. Under the Sea was a 2013 American Gem Trade Association (AGTA) Cutting Edge Award winner.